Wireless charging system with multi-coil scanning and learning

ABSTRACT

A system, recharge apparatus, and method includes transmit coils positioned in a pattern to allow at least one of the transmit coils to establish a wireless link with a receive coil positioned in proximity of the recharge apparatus. A power source is coupled to the transmit coils and configured to selectively energize ones of the transmit coils to transfer power to the receive coil. An energy efficiency detection circuit is configured to detect an electrical response of each one of the transmit coils when energized by the power source, the electrical response indicative of an energy efficiency between the one of the transmit coils and the receive coil. The power source selectively energizes ones of the transmit coils, selected according to a statistical analysis of an historical record and the electrical response indicative of the energy efficiency meeting a minimum efficiency criterion for energy transfer to the receive coil.

RELATED APPLICATIONS

This application claims the benefit of priority to U.S. ProvisionalApplication Ser. No. 62/449,460, filed Jan. 23, 2017, the content ofwhich is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The subject matter disclosed herein generally relates to a wirelesscharging system with multi-coil scanning and learning.

BACKGROUND

Wearable articles, such as footwear, apparel, bracelets, watches, andother wearable electronic devices, often include an internal powersource. The internal power source may include a rechargeable battery anda recharge system for wirelessly receiving power to recharge thebattery. The recharge system may include an external transmit coil thatcouples, e.g., inductively, with an internal receive coil and utilizecurrent induced in the receive coil to recharge the battery.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments are illustrated by way of example and not limitation inthe figures of the accompanying drawings.

FIG. 1 is an exploded view illustration of components of a motorizedlacing system for an article of footwear, in an example embodiment.

FIG. 2 illustrates generally a block diagram of components of amotorized lacing system, in an example embodiment.

FIGS. 3A-3C are depictions of a recharge apparatus, in an exampleembodiment.

FIG. 4 is a block diagram of electronic components of a recharge system,in an example embodiment.

FIG. 5 is a flowchart for operating a recharge system, in an exampleembodiment.

FIGS. 6A-6D are images of a system where the wearable articles arearticles of footwear incorporating the motorized lacing system, inexample embodiments.

FIG. 7 is a flowchart for making a recharge apparatus, in an exampleembodiment.

DETAILED DESCRIPTION

Example methods and systems are directed to a wireless charging systemwith multi-coil scanning and learning. Examples merely typify possiblevariations. Unless explicitly stated otherwise, components and functionsare optional and may be combined or subdivided, and operations may varyin sequence or be combined or subdivided. In the following description,for purposes of explanation, numerous specific details are set forth toprovide a thorough understanding of example embodiments. It will beevident to one skilled in the art, however, that the present subjectmatter may be practiced without these specific details.

Wireless charging systems for wearable articles may include more thanone primary transmit coil. The transmit coils may be placed in or on anarticle so that the transmit coils cover a larger area than may beachieved by a single transmit coil. Thus, for instance, the transmitcoils may be positioned on or in a mat with the centers of the coilsspaced apparat with respect to one another. In such a configuration, thewearable article may be placed on a surface of the mat and the rechargesystem may energize one or more of the transmit coils to induce therecharge current n the receive coil. The recharge system may optionallydetermine that a particular one of the transmit coils are best able toefficiently transfer power to the receive coil based on the current thatmay be driven through each transmit coil and, as a result, select thatparticular one of the transmit coils to energize.

To determine the current being driven through each transmit coil, therecharge system may sequentially energize each coil, measure the currentinduced in the transmit coil, and then select the one of the transmitcoils with the highest current. However, doing so may inevitably andinherently require a noticeable amount of time to sequentially gothrough the various transmit coils. For instance, if it takes one (1)second to assess the efficiency of any given transmit coil, and five (5)transmit coils are included in the recharge system, then five (5)seconds may be needed to identify the most efficient transmit coil. Invarious implementations of the recharge system in relation to a wearablearticle, such as with footwear with a rechargeable battery, delays instarting efficient recharging may be noticeable and particularlyundesirable. For instance, the wearer may seek to recharge the footwearwhile wearing the footwear or may seek to recharge the footwearrelatively quickly during a sporting event, e.g., during a “timeout” ina basketball game or during a halftime break. In such an example, thewearer may readily perceive that multiple seconds are passing withoutrecharging beginning. Moreover, in situations where charging may only bepossible for, e.g., thirty (30) seconds to two (2) minutes, five (5)seconds spent ascertaining which transmit coil is efficiently alignedwith the receive coil may constitute a significant percentage of thetotal time available for recharging and, as a result, meaningfullyreduce the percentage of recharging that may occur.

In particular examples of wearable articles, such in rechargeablefootwear, the position of the receive coil in the wearable article maybe dependent on the size of the wearable article. For instance, while arecharge coil may consistently be positioned in the midsole of anarticle of footwear, owing to the dimensions of the article of footwearthe receive coil may tend to consistently end up efficiently linked witha certain one of the transmit coils when the article of footwear ispositioned with respect to the apparatus including the transmit coils,e.g., a mat. However, because of the difference in size, the receivecoil of a relatively small article of footwear may tend to align with adifferent transmit coil than the receive coil of a relatively largearticle of footwear when otherwise normally placed on the mat, asillustrated herein.

A recharge system has been developed that includes multiple transmitcoils. The recharge system is configured to sequentially energizeindividual transmit coils to identify one of the transmit coils that hasa highest measured efficiency. The recharge system notes which transmitcoils have the highest efficiency over time and dynamically favor thosetransmit coils during the scan. Upon a transmit coil meeting anefficiency threshold condition, that transmit coil may be utilized toconduct, in whole or in part, the recharge session, or a limited numberof the remaining transmit coils may be checked for efficiency over thecourse of the recharge session. In so doing, the recharge system mayquickly settle on a transmit coil that may efficiently provide power tothe recharge coil, lessening the time to recharge and potentiallyimproving the perception of the wearer or owner of the wearable articleof how responsive the recharge system is.

FIG. 1 is an exploded view illustration of components of a motorizedlacing system for an article of footwear, in an example embodiment.While the system is described with respect to the article of footwear,it is to be recognized and understood that the principles described withrespect to the article of footwear apply equally well to any of avariety of wearable articles. The motorized lacing system 100illustrated in FIG. 1 includes a lacing engine 102 having a housingstructure 103, a lid 104, an actuator 106, a mid-sole plate 108, amid-sole 110, and an outsole 112. FIG. 1 illustrates the basic assemblysequence of components of an automated lacing footwear platform. Themotorized lacing system 100 starts with the mid-sole plate 108 beingsecured within the mid-sole. Next, the actuator 106 is inserted into anopening in the lateral side of the mid-sole plate opposite to interfacebuttons that can be embedded in the outsole 112. Next, the lacing engine102 is dropped into the mid-sole plate 108. In an example, the lacingsystem 100 is inserted under a continuous loop of lacing cable and thelacing cable is aligned with a spool in the lacing engine 102 (discussedbelow). Finally, the lid 104 is inserted into grooves in the mid-soleplate 108, secured into a closed position, and latched into a recess inthe mid-sole plate 108. The lid 104 can capture the lacing engine 102and can assist in maintaining alignment of a lacing cable duringoperation.

FIG. 2 illustrates generally a block diagram of components of amotorized lacing system 100, in an example embodiment. The system 100includes some, but not necessarily all, components of a motorized lacingsystem such as including interface buttons 200, a foot presence sensor202, and the lacing engine housing 102 enclosing a printed circuit boardassembly (PCA) with a processor circuit 204, a battery 206, a receivecoil 208, an encoder 210, a motion sensor 212, and a drive mechanism214. The drive mechanism 214 can include, among other things, a motor216, a transmission 218, and a lace spool 220. The motion sensor 212 caninclude, among other things, a single or multiple axis accelerometer, amagnetometer, a gyrometer, or other sensor or device configured to sensemotion of the housing structure 102, or of one or more components withinor coupled to the housing structure 102. In an example, the motorizedlacing system 100 includes a magnetometer 222 coupled to the processorcircuit 204.

In the example of FIG. 2, the processor circuit 204 is in data or powersignal communication with one or more of the interface buttons 200, footpresence sensor 202, battery 206, receive coil 208, and drive mechanism214. The transmission 218 couples the motor 216 to a spool to form thedrive mechanism 214. In the example of FIG. 2, the buttons 200, footpresence sensor 202, and environment sensor 224 are shown outside of, orpartially outside of, the lacing engine 102.

In an example, the receive coil 208 is positioned on or inside of thehousing 103 of the lacing engine 102. In various examples, the receivecoil 208 is positioned on an outside major surface, e.g., a top orbottom surface, of the housing 103 and, in a specific example, thebottom surface. In various examples, the receive coil 208 is a qicharging coil, though any suitable coil, such as an A4WP charging coil,may be utilized instead.

In an example, the processor circuit 204 controls one or more aspects ofthe drive mechanism 214. For example, the processor circuit 204 can beconfigured to receive information from the buttons 200 and/or from thefoot presence sensor 202 and/or from the motion sensor 212 and, inresponse, control the drive mechanism 214, such as to tighten or loosenfootwear about a foot. In an example, the processor circuit 204 isadditionally or alternatively configured to issue commands to obtain orrecord sensor information, from the foot presence sensor 202 or othersensor, among other functions. In an example, the processor circuit 204conditions operation of the drive mechanism 214 on (1) detecting a footpresence using the foot presence sensor 202 and (2) detecting aspecified gesture using the motion sensor 212.

Information from the environment sensor 224 can be used to update oradjust a baseline or reference value for the foot presence sensor 202.As further explained below, capacitance values measured by a capacitivefoot presence sensor can vary over time, such as in response to ambientconditions near the sensor. Using information from the environmentsensor 224, the processor circuit 204 and/or the foot presence sensor202 can update or adjust a measured or sensed capacitance value.

FIGS. 3A-3C is a perspective and cutaway depiction of a rechargeapparatus 300, in an example embodiment. FIG. 3A illustrates aperspective depiction of the recharge apparatus 300. FIG. 3B illustratesa cutaway depiction of the recharge apparatus 300. FIG. 3C illustratesthe recharge apparatus 300 in relation to a user 301 holding articles offootwear (e.g., the articles of footwear 600 described in detailherein).

As illustrated, the recharge apparatus 300 is a recharge mat including ahousing 302 forming a recharge surface 304 on which wearable articles,such as articles of footwear, may be placed. The recharge apparatus 300further includes a plurality of transmit coils 306 configured to createa wireless connection, e.g., an inductive wireless connection, with thereceive coil 208.

In the illustrated example, the recharge apparatus 300 is configuredwith two recharge sections 308, 310 in the example configured torecharge articles of footwear, as illustrated herein. As such, onearticle of footwear 308, e.g., a left shoe, may be placed on onerecharge section 308 while another article of footwear, e.g., a rightshoe, may be placed on the other recharge section 310. Each rechargesection 308, 310 may include its own plurality of transmit coils 306;thus, the first recharge section 308 may include a first plurality ofrecharge coils 306 and the second recharge section 310 may include asecond plurality of transmit coils 306. In an example, each rechargesection 308, 310 has dimensions of approximately eighty (80) millimetersby one hundred (100) millimeters where the transmit coils 306 each havea diameter of approximately forty (40) millimeters. The two rechargesections 308, 310 may be treated for these purposes as separate rechargesystems that happen to operate in conjunction with one another. That isto say, even while each recharge section may operate with a commonelectronics, each recharge section 308, 310 may independently beassessed for which transmit coil 306 within that section is in anefficient alignment with a receive coil 208 and energized for a rechargesession accordingly. However, it is to be recognized and understood thatrecharge apparatuses 300 made according to this specification may bemade with more or fewer recharge sections 308, 310 as appropriate to thewearable article to be recharged. Moreover, for the purposes of thisdisclosure, only one recharge section 308, 310 may be discussed at atime, but it is to be recognized and understood that the principlesdisclosed with respect to the electronics and hardware of one rechargesection 308 may be applied concurrently with and to the other rechargesection 310.

FIG. 4 is a block diagram of electronic components of a recharge system400, in an example embodiment. In various examples, the components ofthe recharge system 400 are all included in the recharge apparatus 300or an alternative, single recharge apparatus. However, it is to berecognized and understood that any of a variety of the components may beincluded remote to the recharge apparatus 300.

Each of the plurality of transmit coils 306 is electrically coupled to apower source 402, an energy efficiency detection circuit 404, anelectronic data storage 406, and a controller 408. The power source 402may be self-contained with a battery or may be coupled to an externalpower source, such as a conventional outlet, such that sufficientvoltage and current is available to energize at least one transmit coil306 at a time sufficient to transfer energy to the receive coil 208according to specified parameters. In various examples, the power source402 may also provide power to operate other components of the system400.

The energy efficiency detection circuit 404 is configured to detect anelectrical response of each transmit coil 306 as that transmit coil 306is energized. The electrical response may be any electrical responsethat is indicative of an efficiency of a connection between the transmitcoil 306 and the receive coil 208. In an example, the energy efficiencydetection circuit 404 is a current meter or ammeter. The efficiency ofthe connection between the transmit coil 306 and the receive coil 208may be proportional to the current induced through the transmit coil 306upon the transmit coil 306 being energized by the power source 402. Upondetecting the current through the transmit coil 306, the energyefficiency detection circuit 404 may transmit that information to thecontroller 408, which may compare the detected current values betweenand among the various transmit coils 306 in order to identify a one ofthe transmit coils 306 that has a highest detected current and,therefore, a highest energy transfer efficiency. The controller 408 mayalso cause the efficiency values as determined to be stored in theelectronic data storage 406. In such an example, the energy efficiencydetection circuit 404 may allow the system 400 to operate withoutinformation from the wearable article.

The efficiency values may function as an historical record of past useof the system 400 generally. The historical record may include all suchefficiency values or may be time-limited, e.g., may include the mostrecent predetermined number of efficiency values obtained, e.g., themost recent ten (10), twenty (20), fifty (50), one hundred (100), ormore, as desired and as may be empirically determined within the contextof the system 400 to provide efficiency values useful for the purposesdescribed herein.

Alternatively, the energy efficiency detection circuit 404 may measurepower delivered to the energized transmit coil 306 and may receive ameasure of the power received by the receive coil 208 and may comparethose two power values. In such an example, the wearable articlegenerally and the motorized lacing system 100 specifically may includethe capacity to measure the power received by the receive coil 208 andtransmit that information to the system 400 and, ultimately, to theenergy efficiency detection circuit 404 and/or to the controller toallow the energy efficiency detection circuit 404 and/or the controllerto compare the energy transmitted vs. the energy received to provide aratio or other measured difference which may be utilized to determinewhich transmit coil 306 is best aligned with the receive coil 208

The controller 408 may cause the power source to serially deliver powerto individual ones of the plurality of transmit coils 306 according totwo modes. The first mode is a test mode, in which one transmit coil 306may be energized at a time according to a predetermined sequence. Thepredetermined sequence may be based on the order in which the transmitcoils 306 have, in prior instances of energizing the transmit coil 306,the highest energy efficiency values as determined above and as storedand accessed by the controller 408 from the electronic data storage. Thesecond mode is a power delivery mode, in which, after one of thetransmit coils 306 is identified as having a suitably high or highestefficiency, that transmit coil 306 is selected as the transmit coil 306to conduct a recharge session. In such an example, the selected transmitcoil 306 delivers power to the receive coil 208 until the rechargesession is ended according to normal parameters, e.g., because thebattery 206 is fully charged, the operator terminates the rechargesession before the battery 206 is fully charged, or another factorcauses the recharge session to terminate (e.g., a safety condition, atimeout condition, etc.).

In examples in which multiple recharge segments 308, 310 are included,each segment 308, 310 may include its own, unique set of transmit coils306 coupled to a common power source 402, energy efficiency detectioncircuit 404, an electronic data storage 406, and a controller 408, witheach of those components configured to interact with multiple sets oftransmit coils 306 simultaneously. Alternatively, each recharge segment308, 310 may be implemented with their own unique set of electroniccomponents. In such an example, recharge apparatus 300 may be understoodto include multiple unique implementation of the recharge system 400,with one recharge system 400 being uniquely implemented in each section308, 310.

FIG. 5 is a flowchart for operating the recharge system 400, in anexample embodiment. While the flowchart is described with respect to therecharge system 400, it is to be recognized and understood that theflowchart may be applied to any suitable system or recharge apparatus ingeneral.

At 500 the controller 408 determines the predetermined sequence byaveraging the recharge efficiency value, e.g., the measured current, ofeach of the last ten (10) efficiency values obtained in the test mode.Thus, for instance, if the transmit coil 306(1) has an average measuredcurrent value over the previous ten sessions of eighty (80) milliamps,the transmit coil 306(2) has an average measured current value of onehundred ten (110) milliamps, the transmit coil 306(3) has an averagemeasured current value of one hundred (100) milliamps, the transmit coil306(4) has an average measured current value of ninety (90) milliamps,and the transmit coil 306(5) has an average measured current value ofone hundred twenty (120) milliamps, the predetermined order may be thetransmit coils 306(5), 306(2), 306(3), 306(4), 306(1).

At 502, the controller 408 selects a highest-ordered one of the transmitcoils 306 that has not yet been tested. In the above example, on thefirst round of the test mode, the transmit coil 306 selected would bethe transmit coil 306(5). In the second round, if the second round isneeded, the transmit coil 306(2) would be selected, and so forth throughthe predetermined sequence until, as detailed below, one of the transmitcoils 306 is selected to do the recharge session or all of the transmitcoils 306 are tested.

At 504, the test mode may proceed by relatively briefly energizing theselected transmit coil 306, e.g., the transmit coil 306(5) in the firstround of the test mode, to obtain an efficiency value for the energizedtransmit coil 306. Thus, in the above example, the controller 408 causesthe power source 402 to energize the transmit coil 306(5) forapproximately one (1) second.

At 506, the current through the selected transmit coil 306 is measuredby the energy efficiency detection circuit 404 as the energy efficiencyvalue.

At 508, the controller 408 receives the energy efficiency value (e.g.,the current as detected) from the energy efficiency detection circuit404 and stores that value in the electronic data storage 406.

At 510, the controller 408 compares the energy efficiency value againsta threshold condition. In an example, if the energy efficiency valuemeets the threshold condition, e.g., meets or exceeds a required value,the controller 408 identities the transmit coil 306 that was tested asthe selected transmit coil 306 and proceeds to 514. Thus, in an example,if the transmit coil 306(5) has an energy efficiency value of onehundred ten (110) milliamps and the threshold condition is to meet orexceed one hundred (100) milliamps, then the threshold condition is metand the controller 408 identifies the transmit coil 306(5) as theselected transmit coil 306.

At 512, if all of the transmit coils 306 have been tested the controller408 selects the one of the transmit coils 306 that has the highestefficiency value in the instant test mode as the selected transmit coil306 and proceeds to 514. If not all of the transmit coils 306 have beentested the controller 408 returns to 502 and selects the next transmitcoil 306 in the predetermined sequence; thus, in the above example, ifthe transmit coil 306(5) was just tested, the transmit coil 306(2) maybe tested next. Thus, in an illustrative example, if none of thetransmit coils 306 meet the threshold condition of one hundred (100)milliamps but the transmit coil 306(3) has the highest measured currentof ninety-five (95) milliamps, then the controller identifies thetransmit coil 306(3) as the selected transmit coil.

At 514, the controller 408 proceeds to the recharge mode and causes thepower source 402 to energize the selected transmit coil 306 and conductan energy transfer session, e.g., a recharge session, with the receivecoil 208 until the energy transfer session is terminated according toconditions described herein and/or are known in the art.

While the flowchart of FIG. 5 describes particular steps, it is to berecognized and understood that periodic variations on the steps may beimplemented as needed. Thus, in an example, if may be desirable toensure that at least two transmit coils 306 are tested in any given testmode. Thus, 510 may be modified to require at least two tests and selectthe transmit coil 306 corresponding to the highest energy efficiencyvalue among the transmit coils 306 tested provided at least one of thosetransmit coils meets the threshold condition. Moreover, it may bedesirable to ensure that all of the transmit coils 306 are tested overtime in order to provide current data for determining the predeterminedsequence. Thus, in an example, if a transmit coil 306 has not beentested over, e.g., a preceding eight (8) test modes then thepredetermined sequence may include such a transmit coil 306 first in thepredetermined sequence or may include as a requirement at 510 to testthat transmit coil at 510, among any of a variety of mechanisms forensuring that all transmit coils 306 are periodically tested.

Further implementations of the system 400 may allow for the transmissionor otherwise inclusion of information from the wearable article to thesystem 400 to further facilitate the determination of the predeterminedsequence at 500. The information may concern physical properties of thewearable article, such as a size of the wearable article. Theinformation may be previously stored in the electronic data storage 406or may be transmitted at the start of a recharge session from thewearable article to the system 400 via the wireless connection betweenone of the transmit coils 306 and the receive coil 208. Alternatively,during the test or recharge mode the information about the wearablearticle may be transmitted and stored in the electronic data storage 406for use in future recharge sessions.

Transmission of the information may be conducted by the wearable articlemodulating the load on the receive coil 208 to adjust the currentthrough the receive coil 208 and, by extension, the current induced inthe energized transmit coil 306. Thus, in an example, a current meter ofthe energy efficiency detection circuit 404 may detect changes incurrent which may be interpretable by the controller 408 as dataproviding the information. Examples in which additional or alternativewireless links, e.g., according to conventional WiFi or Bluetoothwireless modalities, may allow for the direct transmittal of theinformation rather than or in addition to the wireless link between thecoils 208, 306.

FIGS. 6A-6D are images of the system 400 where the wearable articles arearticles of footwear 600 incorporating the motorized lacing system 100,in example embodiments. The recharge apparatus 300 is configured formultiple sizes of the articles of footwear 600 (herein after “shoes”,without limitation on the types of articles of footwear that mayactually be utilized with respect to the recharge apparatus 300). Thus,the recharge apparatus 300 is configured to seat a pair of shoes 600with the pair of shoes 600 being of any of a variety of different sizes600A, 600B without requiring modification to the recharge apparatus 300.Thus, in an example, the pair of shoes 600A may be United States sizeseven (7) shoes while the pair of shoes 600B may be United States sizesixteen (16) shoes, with both pairs of shoes 600A, 600B able to utilizethe recharge apparatus 300 without modification to the rechargeapparatus 300, albeit in various examples not simultaneously.

FIG. 6A illustrates the pair of shoes 600A, 600B in relation to therecharge apparatus 300 and the disparity in size of the pairs of shoes600A, 600B that may still be recharged by the system 400.

FIG. 6B illustrates example positioning of the receive coils 208 betweenthe different pairs of shoes 600A, 600B and the positioning of thetransmit coils 306 within the recharge sections 308, 310. It is notedand emphasized that, owing to the difference in size between the pairsof shoes 600A, 600B, the receive coils 208 in the illustrated examplehave different relative positioning within the pairs of shoes 600A,600B. Thus, the receive coil 208 is more centrally located in the pairof shoes 600A than in the pair of shoes 600B, in which the receive coil208 is relatively more offset.

FIG. 6C illustrates the positioning of the pair of shoes 600A on therecharge apparatus 300 and the positioning of the receive coil 208 inrelation to the transmit coils 306. In particular, the pair of shoes600A is depicted as being in a likely, ordinary position on the rechargeapparatus, with the left shoe 600A′ positioned on the recharge section308 and the right shoe 600A″ on the recharge section 310. It is notedthat, because the recharge apparatus 300 in the illustrated example isflat and does not fixedly secure the shoes 600A in any particularorientation on the recharge surface 304, individual shoes 600A′, 600A″may end up in any of a variety of orientations on the recharge surface304.

In general, it may be likely that a user who recharges the shoes 600Awill tend to place the shoes 600A in a similar orientation when placingthe shoes 600A on the recharge surface 304. The illustrated orientationshows the shoes 600A generally parallel and centered in the respectiverecharge sections 308, 310. However, various users may consistentlyplace the shoes 600A at angles with respect to one another and therecharge apparatus 300, off-centered, and so forth, but may tend to beconsistent with the angle and offset. Thus, while in the generallyparallel and centered orientation illustrated the receive coil 208 maybe expected to align with the transmit coil 306(2), angled and/or offsetorientations may tend to result in any of a variety of the othertransmit coils 306, e.g., transmit coil 306(3), providing the bestefficiency. Because the operations of the controller illustrated in FIG.5, however, if the user is consistent in how the user places the shoes600A on the recharge surface 304, the controller may note that, in thefirst example, the transmit coil 306(2) consistently provides the bestefficiency, the transmit coil 306(2) may consistently be selected as thefirst transmit coil of the predetermined sequence. Similarly, in thesecond example, the transmit coil 306(3) may consistently be selected asthe first transmit coil 306 of the predetermined sequence.

It is noted that if the user is even relatively slightly consistent withhow the shoes 600A are positioned on the recharge surface the controller408 will tend to note the increased frequency with which a givenrecharge coil 306 tends to provide the most efficient connection. Thus,even if one recharge coil 306 provides the most efficient connectiontwenty-five (25) percent of the time, if no other recharge coil 306provides the most efficient connection more often than that then the onerecharge coil 306 may still be placed first in the predeterminedsequence.

It is further noted and emphasized that the two recharge sections 308,310 may be treated separately. As illustrated, the same numberedtransmit coil 306, i.e., transmit coil 306(2), is in the most efficientalignment with the receive coils 208, that is not necessarily the case.Thus, if the user consistently places the shoe 600A′ such that thereceive coil 208 is in alignment with the transmit coil 306(1) of therecharge section 308 but the shoe 600A″ such that the receive coil 208is in alignment with the transmit coil 306(2), the controller 408 mayset the transmit coil 306(1) as the first transmit coil 306 in thepredetermined sequence for the recharge section 308 but the transmitcoil 306(2) as the first transmit coil 306 in the predetermined sequencefor the recharge section 310.

FIG. 6D is an illustration of the shoes 600B in a similar orientation tothat of the shoes 600A in FIG. 6C. However, because of the difference insize between the shoes 600A and 600B, the related receive coils 208 tendto align with different transmit coils 306 between the shoes 600A and600B. Thus, in contrast to the shoes 600A, the predetermined sequencefor a user having shoes 600B who consistently places the shoes 600B inthe illustrated orientation may tend to start with the transmit coil306(1).

It is noted and emphasized that if the user is not consistent with howthe shoes 600 are placed on the recharge surface 304, or if the userplaces shoes 600 of different size on the recharge surface 304 fromsession to session, the predetermined sequence will be less likely tostart with the transmit coil 306 that is in actual alignment with thereceive coil 208. However, the operations of the flowchart of FIG. 5 maystill tend to result the commencement of a recharge session earlier thana recharge apparatus 300 that does not dynamically select the mostefficient transmit coil 306 because the flowchart of FIG. 5 stillprovides for ceasing the test mode upon identifying one of the transmitcoils 306 that meets the threshold condition. Thus, the system 400 maystill be expected, on average, to commence the recharge mode before arecharge system that does not operate according to the flowchart of FIG.5 and the principles disclosed herein.

As disclosed herein, the motorized lacing system 100 generally maytransmit information to the recharge system 400 related to the shoes600. In an example, the motorized lacing system 100 may transmit a shoesize to the recharge system 400. The controller 408 may incorporate suchinformation, e.g., as illustrated herein, in determining thepredetermined sequence. Thus, if the shoe size is seven (7) thecontroller 408 may give a bonus value, e.g., increase the historicalefficiency value by twenty (20) percent, to the transmit coil 306(2) ormay set the transmit coil 306(2) to be first in the predeterminedsequence, while if the shoe size is sixteen (16) the controller 408 mayprovide a bonus value or may set the transmit coil 306(1) to be thefirst in the predetermined sequence. It is noted that, where informationis transmitted via a link between the receive coil 208 and a receivecoil 306 as disclosed herein, the information transfer may occur duringa recharge session after the predetermined sequence has been set. Insuch an example, the information may be saved in the electronic datastorage 406 and utilized in the next recharge session to set thepredetermined sequence, as disclosed herein.

FIG. 7 is a flowchart for making a recharge apparatus, in an exampleembodiment. The recharge apparatus may the recharge apparatus 300 or anyother suitable recharge apparatus. Additionally or alternatively, theflowchart may be utilized to make the system 400 or any other suitablesystem.

At 700, a plurality of transmit coils are positioned in a pattern withina housing of a recharge apparatus to allow at least one of the pluralityof transmit coils to establish a wireless link with a receive coilpositioned in proximity of the recharge apparatus. In an example, thehousing of the recharge apparatus has a recharge surface on which awearable article including the receive coil is configured to be placedto place the receive coil in proximity of at least one of the pluralityof transmit coils.

At 702, a power source is coupled to the plurality of transmit coils,the power source configured to selectively energize ones of theplurality of transmit coils to transfer power to the receive coil.

At 704, an energy efficiency detection circuit is coupled to theplurality of transmit coils, the energy efficiency detection circuitconfigured to detect an electrical response of each one of the pluralityof transmit coils when energized by the power source, the electricalresponse indicative of an energy efficiency between the one of theplurality of transmit coils and the receive coil. In an example, theenergy efficiency detection circuit comprises a current meter andwherein the electrical response is a current induced through theindividual ones of the plurality of transmit coils.

At 706, an electronic data storage configured to store data indicativeof the energy efficiency to generate a historical record of energizingthe plurality of transmit coils is coupled to the energy detectioncircuit.

At 708, a controller is coupled to the electronic data storage and thepower source, the controller configured to cause the power source toselectively energize ones of the plurality of transmit coils, whereinthe at least one transmit coil is selected according to a statisticalanalysis of the historical record and the electrical response indicativeof the energy efficiency meeting a minimum efficiency criterion forenergy transfer to the receive coil, wherein if the selected at leastone coil fails to satisfy the measured electrical response a nexttransmit coil of the plurality of transmit coils is selected. In anexample, the controller is further configured to determine apredetermined sequence of the plurality of transmit coils based on thestatistical analysis of the historical record, and wherein thecontroller is configured to select the next transmit coil of theplurality of transmit coils by selecting an immediately subsequent oneof the plurality of transmit coils from the predetermined sequence. Inan example, the predetermined sequence is further based, at least inpart, on an amount of time since individual ones of the plurality oftransmit coils were selected. In an example, the amount of time isbased, at least in part, on a number of times the controller hasselectively energized at least one of the plurality of transmit coilswithout energizing an individual one of the plurality of transmit coils.In an example, the plurality of transmit coils is a first plurality oftransmit coils and further comprising positioning, in the housing, asecond plurality of transmit coils coupled to the power source and theenergy efficiency detection circuit, wherein the recharge surfaceincludes a first recharge section corresponding to the first pluralityof recharge coils and a second recharge section corresponding to thesecond plurality of recharge coils, wherein the controller is configuredto cause the power source to concurrently selectively energizeindividual ones of the first plurality of transmit coils and individualones of the second plurality of transmit coils based on receive coilsbeing placed in proximity of the first and second recharge sections,respectively.

EXAMPLES

In Example 1, a system includes a recharge apparatus, comprising aplurality of transmit coils positioned in a pattern to allow at leastone of the plurality of transmit coils to establish a wireless link witha receive coil positioned in proximity of the recharge apparatus, apower source coupled to the plurality of transmit coils and configuredto selectively energize ones of the plurality of transmit coils totransfer power to the receive coil, an energy efficiency detectioncircuit coupled to the plurality of transmit coils and configured todetect an electrical response of each one of the plurality of transmitcoils when energized by the power source, the electrical responseindicative of an energy efficiency between the one of the plurality oftransmit coils and the receive coil, an electronic data storage, coupledto the energy detection circuit, configured to store data indicative ofthe energy efficiency to generate a historical record of energizing theplurality of transmit coils, and a controller, coupled to the electronicdata storage and the power source, configured to cause the power sourceto selectively energize ones of the plurality of transmit coils, whereinthe at least one transmit coil is selected according to a statisticalanalysis of the historical record and the electrical response indicativeof the energy efficiency meeting a minimum efficiency criterion forenergy transfer to the receive coil, wherein if the selected at leastone coil fails to satisfy the measured electrical response a nexttransmit coil of the plurality of transmit coils is selected.

In Example 2, the system of Example 1 optionally further includes thatthe controller is further configured to determine a predeterminedsequence of the plurality of transmit coils based on the statisticalanalysis of the historical record, and wherein the controller selectsthe next transmit coil of the plurality of transmit coils by selectingan immediately subsequent one of the plurality of transmit coils fromthe predetermined sequence.

In Example 3, the system of any one or more of Examples 1 and 2optionally further includes that the predetermined sequence is furtherbased, at least in part, on an amount of time since individual ones ofthe plurality of transmit coils were selected.

In Example 4, the system of any one or more of Examples 1-3 optionallyfurther includes that the amount of time is based, at least in part, ona number of times the controller has selectively energized at least oneof the plurality of transmit coils without energizing an individual oneof the plurality of transmit coils.

In Example 5, the system of any one or more of Examples 1-4 optionallyfurther includes that the recharge apparatus has a recharge surface onwhich a wearable article including the receive coil is configured to beplaced to place the receive coil in proximity of at least one of theplurality of transmit coils.

In Example 6, the system of any one or more of Examples 1-5 optionallyfurther includes that the plurality of transmit coils is a firstplurality of transmit coils and further comprising a second plurality oftransmit coils coupled to the power source and the energy efficiencydetection circuit, wherein the recharge surface includes a firstrecharge section corresponding to the first plurality of recharge coilsand a second recharge section corresponding to the second plurality ofrecharge coils, wherein the controller is configured to cause the powersource to concurrently selectively energize individual ones of the firstplurality of transmit coils and individual ones of the second pluralityof transmit coils based on receive coils being placed in proximity ofthe first and second recharge sections, respectively.

In Example 7, the system of any one or more of Examples 1-6 optionallyfurther includes that the energy efficiency detection circuit comprisesa current meter and wherein the electrical response is a current inducedthrough the individual ones of the plurality of transmit coils.

In Example 8, a recharge apparatus includes a plurality of transmitcoils positioned in a pattern to allow at least one of the plurality oftransmit coils to establish a wireless link with a receive coilpositioned in proximity of the recharge apparatus, a power sourcecoupled to the plurality of transmit coils and configured to selectivelyenergize ones of the plurality of transmit coils to transfer power tothe receive coil, an energy efficiency detection circuit coupled to theplurality of transmit coils and configured to detect an electricalresponse of each one of the plurality of transmit coils when energizedby the power source, the electrical response indicative of an energyefficiency between the one of the plurality of transmit coils and thereceive coil, an electronic data storage, coupled to the energydetection circuit, configured to store data indicative of the energyefficiency to generate a historical record of energizing the pluralityof transmit coils, and a controller, coupled to the electronic datastorage and the power source, configured to cause the power source toselectively energize ones of the plurality of transmit coils, whereinthe at least one transmit coil is selected according to a statisticalanalysis of the historical record and the electrical response indicativeof the energy efficiency meeting a minimum efficiency criterion forenergy transfer to the receive coil, wherein if the selected at leastone coil fails to satisfy the measured electrical response a nexttransmit coil of the plurality of transmit coils is selected.

In Example 9, the recharge apparatus of Example 8 optionally furtherincludes that the controller is further configured to determine apredetermined sequence of the plurality of transmit coils based on thestatistical analysis of the historical record, and wherein thecontroller selects the next transmit coil of the plurality of transmitcoils by selecting an immediately subsequent one of the plurality oftransmit coils from the predetermined sequence.

In Example 10, the recharge apparatus of any one or more of Examples 8and 9 optionally further includes that the predetermined sequence isfurther based, at least in part, on an amount of time since individualones of the plurality of transmit coils were selected.

In Example 11, the recharge apparatus of any one or more of Examples8-10 optionally further includes that the amount of time is based, atleast in part, on a number of times the controller has selectivelyenergized at least one of the plurality of transmit coils withoutenergizing an individual one of the plurality of transmit coils.

In Example 12, the recharge apparatus of any one or more of Examples8-11 optionally further includes that the recharge apparatus has arecharge surface on which a wearable article including the receive coilis configured to be placed to place the receive coil in proximity of atleast one of the plurality of transmit coils.

In Example 13, the recharge apparatus of any one or more of Examples8-12 optionally further includes that the plurality of transmit coils isa first plurality of transmit coils and further comprising a secondplurality of transmit coils coupled to the power source and the energyefficiency detection circuit, wherein the recharge surface includes afirst recharge section corresponding to the first plurality of rechargecoils and a second recharge section corresponding to the secondplurality of recharge coils, wherein the controller is configured tocause the power source to concurrently selectively energize individualones of the first plurality of transmit coils and individual ones of thesecond plurality of transmit coils based on receive coils being placedin proximity of the first and second recharge sections, respectively.

In Example 14, the recharge apparatus of any one or more of Examples8-13 optionally further includes that the energy efficiency detectioncircuit comprises a current meter and wherein the electrical response isa current induced through the individual ones of the plurality oftransmit coils.

In Example 15, a method includes positioning a plurality of transmitcoils in a pattern within a housing of a recharge apparatus to allow atleast one of the plurality of transmit coils to establish a wirelesslink with a receive coil positioned in proximity of the rechargeapparatus, coupling a power source to the plurality of transmit coils,the power source configured to selectively energize ones of theplurality of transmit coils to transfer power to the receive coil,coupling an energy efficiency detection circuit to the plurality oftransmit coils, the energy efficiency detection circuit configured todetect an electrical response of each one of the plurality of transmitcoils when energized by the power source, the electrical responseindicative of an energy efficiency between the one of the plurality oftransmit coils and the receive coil, coupling, to the energy detectioncircuit, an electronic data storage configured to store data indicativeof the energy efficiency to generate a historical record of energizingthe plurality of transmit coils, and coupling, to the electronic datastorage and the power source, a controller configured to cause the powersource to selectively energize ones of the plurality of transmit coils,wherein the at least one transmit coil is selected according to astatistical analysis of the historical record and the electricalresponse indicative of the energy efficiency meeting a minimumefficiency criterion for energy transfer to the receive coil, wherein ifthe selected at least one coil fails to satisfy the measured electricalresponse a next transmit coil of the plurality of transmit coils isselected.

In Example 16 the method of Example 17 optionally further includes thatthe controller is further configured to determine a predeterminedsequence of the plurality of transmit coils based on the statisticalanalysis of the historical record, and wherein the controller isconfigured to select the next transmit coil of the plurality of transmitcoils by selecting an immediately subsequent one of the plurality oftransmit coils from the predetermined sequence.

In Example 17, the method of any one or more of Examples 15 and 16optionally further includes that the predetermined sequence is furtherbased, at least in part, on an amount of time since individual ones ofthe plurality of transmit coils were selected.

In Example 18, the method of any one or more of Examples 15-17optionally further includes that the amount of time is based, at leastin part, on a number of times the controller has selectively energizedat least one of the plurality of transmit coils without energizing anindividual one of the plurality of transmit coils.

In Example 19, the method of any one or more of Examples 15-18optionally further includes that the housing of the recharge apparatushas a recharge surface on which a wearable article including the receivecoil is configured to be placed to place the receive coil in proximityof at least one of the plurality of transmit coils.

In Example 20, the method of any one or more of Examples 15-19optionally further includes that the plurality of transmit coils is afirst plurality of transmit coils and further comprising positioning, inthe housing, a second plurality of transmit coils coupled to the powersource and the energy efficiency detection circuit, wherein the rechargesurface includes a first recharge section corresponding to the firstplurality of recharge coils and a second recharge section correspondingto the second plurality of recharge coils, wherein the controller isconfigured to cause the power source to concurrently selectivelyenergize individual ones of the first plurality of transmit coils andindividual ones of the second plurality of transmit coils based onreceive coils being placed in proximity of the first and second rechargesections, respectively.

In Example 21, the method of any one or more of Examples 15-20optionally further includes that the energy efficiency detection circuitcomprises a current meter and wherein the electrical response is acurrent induced through the individual ones of the plurality of transmitcoils.

As used herein, the term “memory” refers to a machine-readable mediumable to store data temporarily or permanently and may be taken toinclude, but not be limited to, random-access memory (RAM), read-onlymemory (ROM), buffer memory, flash memory, ferroelectric RAM (FRAM), andcache memory. The term “machine-readable medium” should be taken toinclude a single medium or multiple media (e.g., a centralized ordistributed database, or associated caches and servers) able to storeinstructions. The term “machine-readable medium” shall also be taken toinclude any medium, or combination of multiple media, that is capable ofstoring instructions (e.g., software) for execution by a machine, suchthat the instructions, when executed by one or more processors of themachine, cause the machine to perform any one or more of themethodologies described herein. Accordingly, a “machine-readable medium”refers to a single storage apparatus or device, as well as “cloud-based”storage systems or storage networks that include multiple storageapparatus or devices. The term “machine-readable medium” shallaccordingly be taken to include, but not be limited to, one or more datarepositories in the form of a solid-state memory, an optical medium, amagnetic medium, or any suitable combination thereof.

Throughout this specification, plural instances may implementcomponents, operations, or structures described as a single instance.Although individual operations of one or more methods are illustratedand described as separate operations, one or more of the individualoperations may be performed concurrently, and nothing requires that theoperations be performed in the order illustrated. Structures andfunctionality presented as separate components in example configurationsmay be implemented as a combined structure or component. Similarly,structures and functionality presented as a single component may beimplemented as separate components. These and other variations,modifications, additions, and improvements fall within the scope of thesubject matter herein.

Certain embodiments are described herein as including logic or a numberof components, modules, or mechanisms. Modules may constitute eithersoftware modules (e.g., code embodied on a machine-readable medium or ina transmission signal) or hardware modules. A “hardware module” is atangible unit capable of performing certain operations and may beconfigured or arranged in a certain physical manner. In various exampleembodiments, one or more computer systems (e.g., a standalone computersystem, a client computer system, or a server computer system) or one ormore hardware modules of a computer system (e.g., a processor or a groupof processors) may be configured by software (e.g., an application orapplication portion) as a hardware module that operates to performcertain operations as described herein.

In some embodiments, a hardware module may be implemented mechanically,electronically, or any suitable combination thereof. For example, ahardware module may include dedicated circuitry or logic that ispermanently configured to perform certain operations. For example, ahardware module may be a special-purpose processor, such as a fieldprogrammable gate array (FPGA) or an ASIC. A hardware module may alsoinclude programmable logic or circuitry that is temporarily configuredby software to perform certain operations. For example, a hardwaremodule may include software encompassed within a general-purposeprocessor or other programmable processor. It will be appreciated thatthe decision to implement a hardware module mechanically, in dedicatedand permanently configured circuitry, or in temporarily configuredcircuitry (e.g., configured by software) may be driven by cost and timeconsiderations.

Accordingly, the phrase “hardware module” should be understood toencompass a tangible entity, be that an entity that is physicallyconstructed, permanently configured (e.g., hardwired), or temporarilyconfigured (e.g., programmed) to operate in a certain manner or toperform certain operations described herein. As used herein,“hardware-implemented module” refers to a hardware module. Consideringembodiments in which hardware modules are temporarily configured (e.g.,programmed), each of the hardware modules need not be configured orinstantiated at any one instance in time. For example, where a hardwaremodule comprises a general-purpose processor configured by software tobecome a special-purpose processor, the general-purpose processor may beconfigured as respectively different special-purpose processors (e.g.,comprising different hardware modules) at different times. Software mayaccordingly configure a processor, for example, to constitute aparticular hardware module at one instance of time and to constitute adifferent hardware module at a different instance of time.

Hardware modules can provide information to, and receive informationfrom, other hardware modules. Accordingly, the described hardwaremodules may be regarded as being communicatively coupled. Where multiplehardware modules exist contemporaneously, communications may be achievedthrough signal transmission (e.g., over appropriate circuits and buses)between or among two or more of the hardware modules. In embodiments inwhich multiple hardware modules are configured or instantiated atdifferent times, communications between such hardware modules may beachieved, for example, through the storage and retrieval of informationin memory structures to which the multiple hardware modules have access.For example, one hardware module may perform an operation and store theoutput of that operation in a memory device to which it iscommunicatively coupled. A further hardware module may then, at a latertime, access the memory device to retrieve and process the storedoutput. Hardware modules may also initiate communications with input oroutput devices, and can operate on a resource (e.g., a collection ofinformation).

The various operations of example methods described herein may beperformed, at least partially, by one or more processors that aretemporarily configured (e.g., by software) or permanently configured toperform the relevant operations. Whether temporarily or permanentlyconfigured, such processors may constitute processor-implemented modulesthat operate to perform one or more operations or functions describedherein. As used herein, “processor-implemented module” refers to ahardware module implemented using one or more processors.

Similarly, the methods described herein may be at least partiallyprocessor-implemented, a processor being an example of hardware. Forexample, at least some of the operations of a method may be performed byone or more processors or processor-implemented modules. Moreover, theone or more processors may also operate to support performance of therelevant operations in a “cloud computing” environment or as a “softwareas a service” (SaaS). For example, at least some of the operations maybe performed by a group of computers (as examples of machines includingprocessors), with these operations being accessible via a network (e.g.,the Internet) and via one or more appropriate interfaces (e.g., anapplication program interface (API)).

The performance of certain of the operations may be distributed amongthe one or more processors, not only residing within a single machine,but deployed across a number of machines. In some example embodiments,the one or more processors or processor-implemented modules may belocated in a single geographic location (e.g., within a homeenvironment, an office environment, or a server farm). In other exampleembodiments, the one or more processors or processor-implemented modulesmay be distributed across a number of geographic locations.

Some portions of this specification are presented in terms of algorithmsor symbolic representations of operations on data stored as bits orbinary digital signals within a machine memory (e.g., a computermemory). These algorithms or symbolic representations are examples oftechniques used by those of ordinary skill in the data processing artsto convey the substance of their work to others skilled in the art. Asused herein, an “algorithm” is a self-consistent sequence of operationsor similar processing leading to a desired result. In this context,algorithms and operations involve physical manipulation of physicalquantities. Typically, but not necessarily, such quantities may take theform of electrical, magnetic, or optical signals capable of beingstored, accessed, transferred, combined, compared, or otherwisemanipulated by a machine. It is convenient at times, principally forreasons of common usage, to refer to such signals using words such as“data,” “content,” “bits,” “values,” “elements,” “symbols,”“characters,” “terms,” “numbers,” “numerals,” or the like. These words,however, are merely convenient labels and are to be associated withappropriate physical quantities.

Unless specifically stated otherwise, discussions herein using wordssuch as “processing,” “computing,” “calculating,” “determining,”“presenting,” “displaying,” or the like may refer to actions orprocesses of a machine (e.g., a computer) that manipulates or transformsdata represented as physical (e.g., electronic, magnetic, or optical)quantities within one or more memories (e.g., volatile memory,non-volatile memory, or any suitable combination thereof), registers, orother machine components that receive, store, transmit, or displayinformation. Furthermore, unless specifically stated otherwise, theterms “a” or “an” are herein used, as is common in patent documents, toinclude one or more than one instance. Finally, as used herein, theconjunction “or” refers to a non-exclusive “or,” unless specificallystated otherwise.

What is claimed is:
 1. A system, comprising: a recharge apparatus, comprising a plurality of transmit coils positioned in a pattern to allow at least one of the plurality of transmit coils to establish a wireless link with a receive coil positioned in proximity of the recharge apparatus; a power source coupled to the plurality of transmit coils and configured to selectively energize ones of the plurality of transmit coils to transfer power to the receive coil; an energy efficiency detection circuit coupled to the plurality of transmit coils and configured to detect an electrical response of each one of the plurality of transmit coils when energized by the power source, the electrical response indicative of an energy efficiency between the one of the plurality of transmit coils and the receive coil; an electronic data storage, coupled to the energy detection circuit, configured to store data indicative of the energy efficiency to generate a historical record of energizing the plurality of transmit coils; and a controller, coupled to the electronic data storage and the power source, configured to cause the power source to selectively energize ones of the plurality of transmit coils, wherein the at least one transmit coil is selected according to: a statistical analysis of the historical record; and the electrical response indicative of the energy efficiency meeting a minimum efficiency criterion for energy transfer to the receive coil, wherein if the selected at least one coil fails to satisfy the measured electrical response a next transmit coil of the plurality of transmit coils is selected; wherein the controller is further configured to determine a predetermined sequence of the plurality of transmit coils based on the statistical analysis of the historical record, and wherein the controller selects the next transmit coil of the plurality of transmit coils by selecting an immediately subsequent one of the plurality of transmit coils from the predetermined sequence.
 2. The system of claim 1, wherein the predetermined sequence is further based, at least in part, on an amount of time since individual ones of the plurality of transmit coils were selected.
 3. The system of claim 2, wherein the amount of time is based, at least in part, on a number of times the controller has selectively energized at least one of the plurality of transmit coils without energizing an individual one of the plurality of transmit coils.
 4. The system of claim 1, wherein the recharge apparatus has a recharge surface on which a wearable article including the receive coil is configured to be placed to place the receive coil in proximity of at least one of the plurality of transmit coils.
 5. The system of claim 4, wherein the plurality of transmit coils is a first plurality of transmit coils and further comprising a second plurality of transmit coils coupled to the power source and the energy efficiency detection circuit, wherein the recharge surface includes a first recharge section corresponding to the first plurality of recharge coils and a second recharge section corresponding to the second plurality of recharge coils, wherein the controller is configured to cause the power source to concurrently selectively energize individual ones of the first plurality of transmit coils and individual ones of the second plurality of transmit coils based on receive coils being placed in proximity of the first and second recharge sections, respectively.
 6. The system of claim 1, wherein the energy efficiency detection circuit comprises a current meter and wherein the electrical response is a current induced through the individual ones of the plurality of transmit coils.
 7. A recharge apparatus, comprising: a plurality of transmit coils positioned in a pattern to allow at least one of the plurality of transmit coils to establish a wireless link with a receive coil positioned in proximity of the recharge apparatus; a power source coupled to the plurality of transmit coils and configured to selectively energize ones of the plurality of transmit coils to transfer power to the receive coil; an energy efficiency detection circuit coupled to the plurality of transmit coils and configured to detect an electrical response of each one of the plurality of transmit coils when energized by the power source, the electrical response indicative of an energy efficiency between the one of the plurality of transmit coils and the receive coil; an electronic data storage, coupled to the energy detection circuit, configured to store data indicative of the energy efficiency to generate a historical record of energizing the plurality of transmit coils; and a controller, coupled to the electronic data storage and the power source, configured to cause the power source to selectively energize ones of the plurality of transmit coils, wherein the at least one transmit coil is selected according to: a statistical analysis of the historical record; and the electrical response indicative of the energy efficiency meeting a minimum efficiency criterion for energy transfer to the receive coil, wherein if the selected at least one coil fails to satisfy the measured electrical response a next transmit coil of the plurality of transmit coils is selected; wherein the controller is further configured to determine a predetermined sequence of the plurality of transmit coils based on the statistical analysis of the historical record, and wherein the controller selects the next transmit coil of the plurality of transmit coils by selecting an immediately subsequent one of the plurality of transmit coils from the predetermined sequence.
 8. The recharge apparatus of claim 7, wherein the predetermined sequence is further based, at least in part, on an amount of time since individual ones of the plurality of transmit coils were selected.
 9. The recharge apparatus of claim 8, wherein the amount of time is based, at least in part, on a number of times the controller has selectively energized at least one of the plurality of transmit coils without energizing an individual one of the plurality of transmit coils.
 10. The recharge apparatus of claim 7, wherein the recharge apparatus has a recharge surface on which a wearable article including the receive coil is configured to be placed to place the receive coil in proximity of at least one of the plurality of transmit coils.
 11. The recharge apparatus of claim 10, wherein the plurality of transmit coils is a first plurality of transmit coils and further comprising a second plurality of transmit coils coupled to the power source and the energy efficiency detection circuit, wherein the recharge surface includes a first recharge section corresponding to the first plurality of recharge coils and a second recharge section corresponding to the second plurality of recharge coils, wherein the controller is configured to cause the power source to concurrently selectively energize individual ones of the first plurality of transmit coils and individual ones of the second plurality of transmit coils based on receive coils being placed in proximity of the first and second recharge sections, respectively.
 12. The recharge apparatus of claim 7, wherein the energy efficiency detection circuit comprises a current meter and wherein the electrical response is a current induced through the individual ones of the plurality of transmit coils.
 13. A method, comprising: positioning a plurality of transmit coils in a pattern within a housing of a recharge apparatus to allow at least one of the plurality of transmit coils to establish a wireless link with a receive coil positioned in proximity of the recharge apparatus; coupling a power source to the plurality of transmit coils, the power source configured to selectively energize ones of the plurality of transmit coils to transfer power to the receive coil; coupling an energy efficiency detection circuit to the plurality of transmit coils, the energy efficiency detection circuit configured to detect an electrical response of each one of the plurality of transmit coils when energized by the power source, the electrical response indicative of an energy efficiency between the one of the plurality of transmit coils and the receive coil; coupling, to the energy detection circuit, an electronic data storage configured to store data indicative of the energy efficiency to generate a historical record of energizing the plurality of transmit coils; and coupling, to the electronic data storage and the power source, a controller configured to cause the power source to selectively energize ones of the plurality of transmit coils, wherein the at least one transmit coil is selected according to: a statistical analysis of the historical record; the electrical response indicative of the energy efficiency meeting a minimum efficiency criterion for energy transfer to the receive coil, wherein if the selected at least one coil fails to satisfy the measured electrical response a next transmit coil of the plurality of transmit coils is selected; determining, with the controller, a predetermined sequence of the plurality of transmit coils based on the statistical analysis of the historical record, and wherein the controller is configured to select the next transmit coil of the plurality of transmit coils by selecting an immediately subsequent one of the plurality of transmit coils from the predetermined sequence.
 14. The method of claim 13, wherein the predetermined sequence is further based, at least in part, on an amount of time since individual ones of the plurality of transmit coils were selected.
 15. The method of claim 14, wherein the amount of time is based, at least in part, on a number of times the controller has selectively energized at least one of the plurality of transmit coils without energizing an individual one of the plurality of transmit coils.
 16. The method of claim 13, wherein the housing of the recharge apparatus has a recharge surface on which a wearable article including the receive coil is configured to be placed to place the receive coil in proximity of at least one of the plurality of transmit coils.
 17. The method of claim 16, wherein the plurality of transmit coils is a first plurality of transmit coils and further comprising positioning, in the housing, a second plurality of transmit coils coupled to the power source and the energy efficiency detection circuit, wherein the recharge surface includes a first recharge section corresponding to the first plurality of recharge coils and a second recharge section corresponding to the second plurality of recharge coils, wherein the controller is configured to cause the power source to concurrently selectively energize individual ones of the first plurality of transmit coils and individual ones of the second plurality of transmit coils based on receive coils being placed in proximity of the first and second recharge sections, respectively.
 18. The method of claim 13, wherein the energy efficiency detection circuit comprises a current meter and wherein the electrical response is a current induced through the individual ones of the plurality of transmit coils. 